The invention relates to wireless communication protocols, and more particularly, to methods of dynamic channel allocation for access points in wireless networks.
In conventional wireless local area network (WLAN) environments complying with Institute of Electrical and Electronic Engineers (IEEE) 802.11 communication standards, to enhance communication ability and accommodate a greater number of mobile hosts (MH), multiple access points (AP) are located in a communication area, for example, in a schools building or airport, such that a mobile host anywhere in the building can receive wireless signals. Network administrators statically deploy network access points and allocate communication channels therefor, manually deriving communication channels for each access point, such that signal interference between access points is minimized, and communication channels allocated to access points will not be reallocated. Access points described herein serve as bridges in wireless networks, connecting conventional wired LANs and wireless LANs, such that a personal computer equipped with an wireless card can share resources from LANs or wide area networks (WANs). Additionally, access points provide network management functions, controlling and managing personal computers connected thereto via wireless cards.
The number of available communication channels is limited in that many access points use identical or adjacent channels if a considerable number of access points are located in the same area, resulting in signal interference if two neighboring access points use identical or adjacent channels. However, mobile hosts may not equally associate with each access point. If there is no mobile host which associates with one of two adjacent access point and is present in the signal coverage of the access points, the two access points can use the same channel and it may reduce the possibility of signal interference caused by access points with high channel load. Referring to FIG. 1A, both access points AP1 and AP4 are allocated communication channel C1, access point AP2 is allocated communication channel C6, and access point AP3 is allocated communication channel C11. Mobile host MH6 associates with access point AP1, mobile hosts MH7˜MH11 associate with access point AP2, mobile hosts MH12˜MH14 associate with access point AP3, and mobile hosts MH15 and MH16 associate with access point AP4. Referring to FIG. 1B, when mobile hosts MH7˜MH11 disassociate with access point AP2 and associate with access point AP1, the possibility of signal interference between access points AP1 and AP4 may increase due to the channel load of access point AP1 increase and the same communication channel to access point AP4.
Thus, a method for dynamic channel allocation for access points in wireless networks is desirable.